Coating compound



Patented s er. 20, 1938 2,130,924

2.130.934 ooa'rmo oomoorm Arthur W. Johnson and George H. Young, Pittsburgh, Pa" assignors to Stoner-Mudge, Inc., a corporation 02- Pennsylvania N Drawing. Application February 5, 1937, Serial No. 124,236

6 Claims. (Cl. 134-26) This invention relates to a coating compound polymeric vinyl compound specifically named capable of.formlng protective coatings upon the above a pitch containing one or more of the tar surfaces of other bodies, and relates specifically bases which boil at temperatures higher than to a coating compound consisting primarily of 240 C. at atmospheric pressure, an applied coatcertain of those resinous polymeric vinyl coming of the mixture possesses greatly increased 5 pounds known commercially as Vinylite. These thermal stability,'this increase in thermal stacompounds, as is well known, are the polymers bility being noticeable upon the addition of even and co-polymers of various vinyl compounds, a trace of the pitch. The term tar base" is a such polymers and co-polymers being of reschemical term, and defines any one of the higher 10 inous nature. Amongst the resinous polymeric pyridine base homologs boiling at atmospheric 10 vinyl compounds there may be given as typical pressure above 240 C. that occur naturally in polyvinyl acetate, polyvinyl propionate, polyvinyl coal tar, natural asphalts, water-gas pitch, bone chloride, polyvinyl bromide, polyvinyl chloropitch, and other tarry materials.

bromide, polyvinyl chloro-acetate, polyvinyl Having further discovered that it is the tar chloro-propionate, and polyvinyl chloro-alcohol. bases of higher boiling range which give the de- 15' Generally stated, the resin-type substance with sired efiect, we are able to add these tar bases which we are concerned consists of any polymer, either as isolated products, in the form of a co-polymer, or polymeric mixture of the compurified pitchy wax containing the bases, or in pound responding to the formula CH2=CH-X, the form of a crude pitch. We have successfully in which X may be a halogen, the hydroxyl group, utilized, to impart thermal stability to the Vinyl- 20 acetoxyl, propionoxyl, or in general any monoite film, coal tar pitch, natural asphalt. bone carboxylic acyloxyl group. In the ensuing claims pitch, and water-gas pitch, it being thus apthe term polymer will be understood to be inparent that the tar bases are effective for our elusive of polymers, co-polymers, and polymeric purpose, whether they be derived from natural mixtures. And, specifically, we have found suitor synthetic pitches, being typically similar in 25 ed to'our purpose those resinous products that their general chemical structure and nitrogen result from the simultaneous polymerization of content. In a companion application filed July vinyl chloride and vinyl acetate. 28, 1938, Serial No. 221,799, we claim a broader The object of our invention is to add to such field of invention within which the invention resinous polymeric vinyl compounds a substance of this application is a species.

which will serve to impart thermal stability to We shall give the iollowing exemplary pm- & l consisting p i y f h P lymeric vinyl cedure for increasing thermal stability of the compounds F r mple, a normal polymeric Vinyllte film, utilizing as typical of a tar base vinyl film deposited upon metal tends to detechnical quinoline (boiling slightly above 240 p e at i e y W temperatures if it is 0.), this being one of the higher boiling point 35 as heavy as is usualfor films of this nature ex-' pyridine bases derived from coal tar. Taking 100 c d s n w h 7 i ram p square inch grams of a 20% solution of the product of poly- T e pec fic d compo itio emp r tur v ry merization, the solvent being desirably a mixture somewhat with different metal to which the film of the typical ketone solvents for the polymeric 40 is applied. For some of the most used metals vinyl resins, together with a mixed aromatic 40 e decomposition temperatures may be given 88 thinner, we added 0.2 gram of technical quincfollows: line. The polymeric vinyl solution with the added 1 v F. technical quinoline was then spread on tin plate Tin plate 300 and was baked for 15 minutes at a temperature Iron 290 of 380 F. The'applied film did not exhibit any 45 Zinc 2 decomposition at that temperature, and by test- Copper 330 ing'we found that it was not until the film on It is, therefore, a matter of desirability. and the tin Plate was Subjected to p a ur specifically our object herein, so to increase the o y p ew g 4 0 F. that thermal dethermal stability of the polymeric vinyl film compo o b 50 that, as applied to such metals, or to other metal An equal proportional quantity of the other and materials, it will endure temperatures subpyridine bases, boiling higher than technical stantially higher than those noted without underquinoline, gives identical results. It a crude pitch going decomposition. i be analogously used, 0.4 gram according to the We have found that by adding to the resinous example, or 2% the weight oi the polymeric 55 vinyl resin, in accordance with the general proportion, should be used in order to obtain a .result identical with that obtained by the use of 0.2 gram of technical quinolin If pitch-derived waxes be used, they having been deprived of a proportion of their tar base content in removal of carbon and other impurities of the pitch, they should be utilized in double the quantity of the pitch; that is. 4% as a general proportion and 0.8 gram in accordance with the example, in order to obtain a result identical with that obtained by use of the technical quinoline. It may be explained that in the base of crude pitch, and pitchderived waxes, a large proportion of the content constitutes for our purpose merely a pitchy diluent for the tar base or bases supplied to the coating. For reasons of availability, however, it may under certain ciircumstances be desirable to utilize a crude pitch or pitch-derived wax, rather than to add technical quinoline or other tar bases in separated condition. In this connection it should be .understood that the pitches are throughout their entire boiling range satisfactory for our purpose. I

As an alter-native to admixture of the thermal stabilizing material to the polymeric vinyl resin 1 in solution, it may-in any of its forms be milled in any of its forms.

' m such proportion that the coating becomes a pitchy coating rather than a Vinylite film, and it is equally true that there would be no advantage in attempting to. carry the endurable temperature to such point that the thermal stabilizing agent would itself decompose.

I Increase in the thermal stability of a Vinylite film presents marked practical advantage, in that as so stabilized the film may be subjected to baking at increased temperatures, and as a result a marked improvement in adhesion to the surfaces being coated, and in resistance to moisture and other corrosive influences, is efiected.

.Also as applied to'a metal, the metal coated with a Vinylite film of increased thermal stability is capable, as, a material or article, of being subjected to temperatures of increased severity without destruction oi the coating thereon.

We claim as'our invention:

1. A thermallystabilizedcoating compound consisting of a polymer ofa substance responding to the formula CHz=CH-X, in which X is a substance acyloxyl groups, and

aieaeaa of a group consisting of the halogens, the hydroxyl group, and the monocarboxylic acyloxyl groups, and a pitch containing at least one tar base boiling above 240 C. at atmospheric pressure, such tar base being present in a ratio not exceeding two parts of tar base to one hundred parts of the first named substance.

2. A- thermally stabilized coating compound comprising a polymer of a substance responding to the formula CH2=CH-X, in which X is a substance of a group consisting of the halogens, the hydroxyl group, and the monocarboxylic acyloxyl groups, and a stabilizer consisting of a pitch containing at least one tar base boiling above 240 C. at atmospheric pressure in a diluent carrier of pitchy nature, such tar base being present in a ratio not exceeding two parts of tar base to one hundred parts-oi the first named substance.

3. A thermally stabilized coating compound comprising a polymer of a substance responding to the formula CHz=CI-IX, in which X is a substance of a group consisting of the halogens, the hydroxyl group, and the monocarboxylic acyloxyl groups, and a stabilizer consisting of technical quinoline, such stabilizer being present in a ratio not exceeding two parts of quinoline to one hundred parts of the first named substance.

4. A thermally stabilized coating, compound comprising a polymer of a substance responding to the formula CHz=CH-X,' in which'X is a substance 01 a group consisting of the halogens, the hydroxyl group, and the monocarboxylic a stabilizer consisting of a tar wax containing at least one tar base boiling above 240 C. at atmospheric pressure, su'ch tar base being present in a ratio not exceeding two parts of tar base to one hundred parts of the substance first named.

5. A thermally stabilized coating compound comprising the resinous product of the polymerization of vinyl chloride amba stabilizer consisting of a pitch containing at least one tar base boiling above 240 C. at atmospheric pressure,

such tar base being present in a ratio not exceeding two parts of tar base to one hundred'parts of the resinous product.

6; A thermally stabilized coating compound comprising the resinous product of the simultane ous polymerization of vinyl chloride and vinyl acetate together with a stabilizer consisting of 'a pitch containing at least one tar base boiling above 2&0 C. at atmospheric pressure, such tar base being present in a ratio not exceeding two parts of tar base to one hundred parts of the resinous product.

mm W. JOHNSON. GEORGE H. YOUNG. 

